تشخيص RELSTONIA SOLANACEARUM در غده هاي بذري سيب زميني و خاك با استفاده از تكنيك PCR -

DIAGNOSIS OF RALSTONIA SOLANACEARUM IN POTATO SEED TUBERS AND SOIL, USING PCR TECHNIQUE

Ralstonia solanacearum, the causal agent of bacterial wilt, is an important pathogen of potato reducing yield in tropical and sub tropical regions. This pathogen is easily transmitted from one field to another by planting healthy looking seed tubers with latent infection. Development of a sensitive and rapid technique for diagnosis of R. solanacearum is crucial for efficient control of this disease. Therefore, PCR-based molecular diagnosis of R. solanacearurn was studied. Application of this technique using specific primers, 759 and 760, amplified a DNA fragment of 281bp. The ordinary PCR technique could only detect 10^4 CFU/ml of R. solanacearum, while after an enrichment stage of 48 hours bacterial concentration of 10 CFU/ml was detectable. Detection was accomplished using both stem and tuber tissues in three commercial potato cultivars Herta, Nicola and Fiana. PCR detection of R. solanacearm in soil samples was also successful post-enrichment of bacterial concentration in the sample. Enrichment of pathogen population in the sample leads to extraction of high quality DNA and dilution of soil inhibitors in the DNA solution and consequently enhances the fidelity and reliability of PCR detection in soil samples.